Rob Decker, a Voyager Low-Energy Charged Particle Instrument co-investigator from the Johns Hopkins University Applied Physics Laboratory, said: "We've been using the flow of energetic charged particles at Voyager 1 as a kind of wind sock to estimate the solar wind velocity. We've found that the wind speeds are low in this region and gust erratically. For the first time, the wind even blows back at us. We are evidently traveling in completely new territory. Scientists had suggested previously that there might be a stagnation layer, but we weren't sure it existed until now."

This is called the heliopause--the place where the solar wind is no longer clear in its direction.